I am using an iPad as an iBeacon with CoreLocation. Is it possible to have the iPad connect to another BLE device (non iBeacon) using CoreBluetooth?
Yes. An iOS Bluetooth "Central" can connect to a Bluetooth LE Peripheral, and at the very same time act as a Bluetooth "Peripheral" and advertise an iBeacon packet. CoreBluetooth supports both modes simultaneously.
I have built several apps that do exactly this.
The only trick is that to advertise, the app must be in the foreground with the screen on.